• International Journal of Oral Biology
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• 제30권3호
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• pp.91-98
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• 2005

Gamma-aminobutyric acid (GABA) is known as an inhibitory neurotransmitter in the neurons of the central nervous system. However, its detailed action mechanisms in the rostral gustatory zone of the nucleus tractus solitarius (rNTS) have not been established. The present study was aimed to investigate the distribution, role and action mechanisms of GABA in rNTS. Membrane potentials were recorded by whole cell recordings in isolated brain slices of the rat medulla. Superfusion of GABA resulted in a concentration-dependent reduction in input resistance in the neurons in rNTS. The change in input resistance ws accompanied by response to a depolarizing pulse were diminished by GABA. Superfusion of the slices with either $GABA_A$ agonist, muscimol, $GABA_B$ agonist, baclofen or $GABA_C$ agonist, TACA, decreased input resistance and reduced the nerve activity in association with membrane hyperpolarization. It is suggested that inhibitory signals playa role in sensory processing by the rNTS, in that GABA actions occur through activation of $GABA_A,\;GABA_B\;and\;GABA_C$ receptor. These results suggest that GABA has an inhibitory effect on the rNTS through an activation of $GABA_A,\;GABA_B\;and\;GABA_C$ receptors and that the GABAergic inhibition probably plays an important role in sensory processing by the rNTS.

• Animal cells and systems
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• 제15권1호
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• pp.29-36
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• 2011

Insect lysozymes are basic, cationic proteins synthesized in fat body and hemocytes in response to bacterial infections and depolymerize the bacterial cell wall. The c-type lysozyme of the insect Spodoptera litura (SLLyz) is a single polypeptide chain of 121 residues with four disulfide bridges and 17 rare codons and is approximately 15 kDa. The full-length SLLyz cDNA is 1039 bp long with a poly(A) tail, and contains an open reading frame of 426 bp long (including the termination codon), flanked by a 54 bp long 5' UTR and a 559 bp long 3' UTR. As a host for the production of high-level recombinant proteins, E. coli is used most commonly because of its low cost and short generation time. However, the soluble expression of heterologous proteins in E. coli is not trivial, especially for disulfide-bonded proteins. In order to prevent inclusion body formation, GST was selected as a fusion partner to enhance the solubility of recombinant protein, and fused to the amplified products encoding mature SLLyz. The expression vector pGEX-4T-1/rSLLyz was then transformed into E. coli BL21(DE3)pLysS for soluble expression of rSLLyz, and the soluble fusion protein was purified successfully. Inhibition zone assay demonstrated that rSLLyz showed antibacterial activity against B. megaterium. These results demonstrate that the GST fusion expression system in E. coli described in this study is efficient and inexpensive in producing a disulfide-bonded rSLLyz in soluble, active form, and suggest that the insect lysozyme is an interesting system for future structural and functional studies.

• Archives of Pharmacal Research
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• 제29권6호
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• pp.490-496
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• 2006

This study aimed to evaluate in vitro effects of Rheum undulatum L. root on the development of dental caries, especially its effects on viability, dental plaque formation, and glycolytic acid production of Streptococcus mutans and Streptococcus sobrinus. Methanol extract of Rheum undulatum L. root and its fractions were prepared and tested. Among the test extract and fractions, dichloromethane fraction (DF) showed the most active antibacterial activity (inhibition zone: 13-17 mm) against S. mutans and S. sobrinus in a disc diffusion method. Minimal inhibitory concentrations (MICs) of DF against these bacteria ranged from 0.25 to 0.5 mg/mL. Furthermore, DF significantly inhibited the caries-inducing factors of these bacteria. At sub-MIC levels, DF inhibited in vitro dental plaque formation by S. mutans and S. sobrinus ($IC_{50}$= 0.079 and 0.142 mg/mL, respectively), which was caused, in part, by the inhibitory effect on the activity of glucosyltransferases. A significant reduction of glycolytic acid production was found at the concentration as low as 0.032 mg/mL for S. mutans and 0.063 mg/mL for S. sobrinus. The possible bioactive compounds that are inducing in vitro anti-cariogenic activity of DF are unknown. Based on the preliminary phytochemical analysis, the activity of DF may be related to the presence of anthraquinones, cardiac glycosides, coumarines, sterols/terpenes, and phenolics. These results indicate that DF is probably useful for the control of dental plaque formation and subsequent dental caries development.

• 대한약침학회지
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• 제14권1호
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• pp.79-86
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• 2011

Objective : This study was performed to compare anti-inflammation, anti-oxidation and anti-bacterial effects of Cuscutae Semen(CS) extracted with two kinds of solvents, ethanol and distilled water. Methods : Two kinds of CS extractions were prepared 20, 50, 100 ${\mu}l/mg$. The cytotoxicity was measured by MTT assay in Raw 264.7 cell. The anti-inflammation effect was measured by inhibitory efficacy of NO Production in Raw 264.7 cell. The anti-oxidation effect was measured by DPPH Radical scavenging ability in HaCaT cell. The anti-bacterial effect was measured by inhibition zone diameter on Propionibacterium acnes. Results : 1. Two kinds(100 ${\mu}l/mg$) of CS extraction groups had 50% cytotoxicity in Raw 264.7 cell. 2. All of CS extraction groups were not showed significantly inhibitory effect on NO production. 3. All of CS extracted with ethanol only showed dose-dependently significantly scavenging effect of DPPH radicals. 4. Two kinds of CS extractions did not have a inhibitory effect on Propionibactrium acnes. Conclusion : Two kinds(100 ${\mu}l/mg$) of CS extraction groups have 50% cytotoxicity. Two kinds of CS extractions have not the inhibitory effect on NO production and Propionibactrium acnes. CS groups extracted with ethanol only have a significantly scavenging ability of DPPH radicals. This study suggests that CS extracted with ethanol was effective in anti-oxidation.

• 대한약침학회지
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• 제14권1호
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• pp.71-78
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• 2011

Objective : This study was performed to compare anti-inflammation, anti-oxidation and anti-bacterial effects of Ligustici Rhizoma (LR) extracted with two kinds of solvents, ethanol and distilled water. Methods : It is prepared two kinds of LR extracts 20, 50, 100 ${\mu}l/mg$ by first. MTT assay way to measure cytotoxicity is formed in Raw 264.7 cell. The anti-inflammation effect is measured by ability to inhibit production of NO in Raw 264.7 cell. The anti-oxidation effect was measured by DPPH Radical scavenging ability in HaCaT cell. The anti-bacterial effect was measured by inhibition zone diameter on Propionibacterium acnes. Results : 1. LR (20 ${\mu}l/mg$) extracted with ethanol was showed 80% cytotoxicity, LR (50 ${\mu}l/mg$) extracted with ethanol and LR (20, 50 ${\mu}l/mg$) extracted with water were showed 70% cytotoxicity, LR (100 ${\mu}l/mg$) extracted with ethanol and LR (100 ${\mu}l/mg$) extracted with water were showed 60% cytotoxicity in Raw 264.7 cell. 2. LR (100 ${\mu}l/mg$) extracted with ethanol was showed more significantly inhibitory effect on NO production than the water extraction. 3. Two kinds of LR extraction groups did not show significantly scavenging effect of DPPH radicals. 4. Two kinds of LR extractions did not have a inhibitory effect on Propionibactrium acnes. Conclusion : Two kinds of LR extracts have not cytotoxicity, statistically significant ability to scavenge DPPH radicals and effect to inhibit Propionibactrium acnes. LR extracted with ethanol only have a little effect to inhibit NO production. This study proposes that LR extracted with ethanol is more effective in anti-inflammation.

• Journal of Welding and Joining
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• 제18권2호
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• pp.176-176
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• 2000

Recently developed Austenite stainless steel,309L was to overlay on 3Cr-1Mo-V-Ti-B steels, using Electroslag welding process, which wide electrodes were adopted. Transition region in welding interlayer relating to disbonding crack was investigated. Also. the effect of welding condition on the width of transition region and coarsening grains of the austenite were studied.1) With increasing welding speed the width of martensite at transient region was increased, but the amount of delta ferrite in weld metal was reduced, being fine grained.2) The form of martensite at the transition region was occured by reversible transition region, leading to increasing Ms point.3) With increasing welding speed, the grain of austenite formed at the welding interface was finer. With increasing welding current under the same welding speed, the grain size of the austenite was finer. At high current, original grain size of the austenite is coarse, but the austenite has fine grains because the austenite was transformed to martensite during cooling.4) In the case of high welding speed, the width of martensite at the welding interface was increased, but the grain size of austenite at the welding interface was finer. This indicates that the inhibition of disbonding crack may be achieved through dispersening fine carbides in the grain boudary.(Received August 3, 1999)

• Journal of Welding and Joining
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• 제18권2호
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• pp.49-56
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• 2000

Recently developed Austenite stainless steel, 309L was used to overlay on 3Cr-1Mo-V-Ti-B steels, using Electroslag welding process, which wide electrodes were adopted. Transition region in welding interlayer relating to disbonding crack was investigated. Also, the effect of welding condition on the width of transition region and coarsening grains of the austenite were studied. 1) With increasing welding speed the width of martensite at transient region was increased, but the amount of delta ferrite in weld metal was reduced, being fine grained. 2) The form of martensite at the transition region was occurred by reversible transformation during cooling since the interdiffusion of Cr and Ni from weld metal and Fe and C from base metals at the transition region, causes to lowering the concentration of Cr and Ni at the transition region, leading to increasing Ms point. 3) With increasing welding speed, the grain of austenite formed at the welding interface was finer. With increasing welding current under the same welding speed, the grain size of the austenite was finer. At high current, original grain size of the austenite is coarse, but the austenite has fine grains because the austenite was transformed to martensite during cooling. 4) In the case of high welding speed, the width of martensite at the welding interface was increased, but the grain size of austenite at the welding interface was finer. This indicates that the inhibition of disbonding crack may be achieved through dispersening fine carbides in the gain boundary.

• 미생물학회지
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• 제54권3호
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• pp.244-253
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• 2018

이 연구는 분리된 토양 세균에 의해 생성된 항균물질의 효과를 평가하기 위해 수행되었다. 2000여개의 세균 분리주 중 Paenibacillus elgii DS381이 여러 인간 피부 상재균과 병원성 세균에 대해 높은 항균활성을 나타내었다. DS381 균주는 agar well diffusion test에서 모든 대상 세균과 효모에 대해 15.3~26.0 mm 직경의 저해대를 형성하였다. DS381이 생성한 항균 펩티드는 모든 대상 미생물에 낮은 최소저해농도 (0.039-5.000 mg/ml)를 나타내었다. DS381 균주는 lipopeptide 같은 생물계면활성제 생산을 나타내었는데, 배양 상등액의 표면장력을 60.0에서 40.3 mN/m으로 낮추었다. DS381은 또한 $1.56{\pm}0.13U/ml$의 chitinase 활성도 나타내었다. 이 결과들은 P. elgii DS381이 일부 중요한 인간 피부 상재균과 병원성 세균에 대한 효율적인 생물제어제로 사용될 수 있음을 가리킨다.

• 생명과학회지
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• 제22권3호
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• pp.373-379
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• 2012

본 연구에서는 계피 초임계 추출물(SFE oil)과 박 추출물(SFM), 80% methanol 추출물, cinnamaldehye의 항균, 항산화력을 비교하였다. 그 결과 추출조건에 따라 뚜렷한 효과의 차이를 나타내었으며, 80% methanol 추출물과 SFM이 강력한 항산화능 보였다. 반면에 항균효과에서는 cinnamaldehyde와 SFE oil에서 식중독균에 대한 항균효과가 뛰어났으며, 초임계를 이용한 추출에서 cinnamaldehyde 이외에 다른 camphene, cineole, eugenol 등의 정유성분들이 항균효과에 영향을 미친 것으로 생각된다. 이러한 결과로부터, 초임계 추출법이 항균물질 및 정유성분 추출에 매우 용이할 뿐만 아니라, 초임계 추출 후 폐기되고 있는 박에서도 유용성분이 함유되어 있음을 확인하였으므로 계피의 초임계 추출물 및 박 추출물 모두 기능성 천연소재로의 활용이 가능할 것으로 기대된다.

• 한국축산식품학회지
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• 제27권4호
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• pp.543-547
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• 2007

본 연구에서는 원유와 사일리지, 전통발효식품 등으로부터 유방염 원인균에 대한 항균성을 가지는 유산균을 분리하였고, 이들 중 원유에서는 79, 91-3 균주와 전통발효식품에서는 SA131, NK24, NK34, 32, 44-1 균주, 사일리지에서는 253, 261, 262, 263, 265 균주, 닭분변에서 B32, C23 균주에서 유방염 원인균에 대한 비교적 높은 항균력을 확인할 수 있었다. 이를 통해 새로운 항생제 대체물질의 가능성을 확인할 수 있었다.